Carbon Nano tubes could have some advantages I think over copper in the design of electromagnets should they ever be manufactured in great lengths and purity. Carbon nanotubes are fairly good conductors of electricity length wise, and terrible conductors on their surfaces so it would appear they would make good magnet wire. you don't even need a coating. Though they could only transport a microscopic fraction of the current from even the finest wire, you can potentially have millions of times the number of turns. Might be no good for nuclear applications if the nuclear products break down the wires.

The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)